反意疑问句的有关疑惑

—I spent a week in Xiamen last month.

—Then you must have been overcharged for sea food many a time, ________ you? This city is known for that.

A. mustnt B. werent C. havent D. hadnt

老师，这题选B，是由于表示对过去的推断吗，所以翻译疑问用werent you 吗？

Then you must have been overcharged for sea food many a time, werent you?

这句话叫做“反意疑问句”。前半部分中的 must have been，是对过去状况的推断（上文有last month 这个过去时间），实质表达“一般过去时” 的意义。

youmust have beenovercharged = you were surely overcharged

既然前半句是were，那样，后面的“附加问句”，用werent 给予补充。

【注意】附加问句不是不可以重复情态动词，而是must 表推断只用于一定，不需要于否定。must 一旦否定，就不是推断了，而是“不许；不准”。

C,D 两个答案，都是完成时，与前句时态不符。